# # 使用 + 针对两个列表进行拼接
# a = [1,2,3,4]
# b = [5,6,7]
# c = a + b
# print(c)
# print(b)
# print(a)
# 使用extend进行拼接，把后一个列表内容拼接到前一个列表里面
a = [1,2,3,4]
b = [5,6,7,8]
# a.extend(b)
c = a.extend(b)
print(a)
print(b)
print(c)
d = [2,3,4,5,6]
c = [9,3,6,7,8]
d += c
print(d)